1. Field of the Invention
This invention pertains to apparatus for dispensing liquids, and more particularly to an easily cleanable apparatus for dispensing predetermined quantities of liquids.
2. Description of the Prior Art
Apparatus for dispensing liquid and semi-liquid materials are well known. U.S. Pat. Nos. 1,865,990 and 2,678,753 are representative of pumps in which check valves are employed to properly direct the flow of the liquids from the reservoirs to the fluid outlets. The pump mechanisms employ a single housing which contains both the check valves and the piston assemblies utilized to produce the pumping action. In each disclosed apparatus, the liquid is ejected through a spout formed in the pump housing. It will be noticed that the pumping mechanisms are immersed within the liquids being dispensed. It is also apparent that the pumping mechanisms in both patents are assembled to the reservoirs so as to form unitary and permanent dispensers. Thus, disassembly and cleaning of the pumping mechanisms and reservoirs is not practical.
U.S. Pat. Nos. 2,622,539 and 2,765,964 illustrate stationary devices for dispensing metered quantities of liquid soap contained in reservoirs located above the pumping mechanism. Each pumping mechanism includes a spring-biased piston and a check valve arrangement for controlling the liquid flow. Both the pistons and the check valves are contained within a pump housing. The pumping mechanism is located outside of the reservoir, which is undesirable if the dispensing device must occupy a minimum amount of space. The soap is dispensed directly through openings formed in the pump housing. It is apparent that disassembly and cleaning of these two dispensers is a relatively difficult and time-consuming chore.
U.S. Pat. No. 4,105,146 shows another version of a stationary soap dispenser. The reservoir is located above the pumping mechanism. An intricately machined piston, together with two seals, are used in place of check valves to control the soap flow through the dispenser. The soap is ejected through an orifice which passes through both the pump housing and a surrounding housing formed integrally with the bottom of the reservoir. The configuration of the piston and other components limits application of this device to very viscous products. Although the pumping mechanism may be relatively easily disassembled, the intricacies of the piston passages renders this design very difficult to clean. The position of the pumping mechanism outside of the reservoir may be undesirable if a compact dispenser is required.
Thus, a need exists for pumping apparatus which is capable of dispensing relatively thin liquids and which may be quickly and easily disassembled for cleaning so that it can be used for consumable products.